JP2004328232A - Microphone with windshield and electrostatic shield function, and windshield and electrostatic shield screen used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microphone which can be easily manufactured, has a high windshield property and an electrostatic shield effect, can specifically be provided close to another electronic circuit and the like, can improve the degree of freedom in design, and can be widely applicable to a communication device, an audio device, a measurement instrument and a system thereof. <P>SOLUTION: The microphone 1 is provided with a windshield function and an electrostatic function by mounting a sheet-like screen 3 made of a sound transmitting material on the front face of a housing 2 so that the screen 3 covers the sound hole 2A provided on the front face of the conductive housing 2. The screen 3 has an outer diameter larger than that of the sound hole 2A and smaller than that of the front face of the housing 2, and a conductive material 4 is coated continuously on the screen 3 and the front face of the housing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a microphone with a windshield and electrostatic shield function having an electrostatic shield effect that can be installed close to other electronic circuits and the like, and a windshield and electrostatic shield screen used for the microphone.
[0002]
[Prior art]
When the wind hits the microphone, for example, when the microphone is picked up outdoors, turbulence is generated by the microphone, so-called wind noise is generated and noise occurs, and the original function and performance of the microphone are significantly deteriorated. Also, in the recording of voice and the like, the exhalation becomes a kind of wind, and the same phenomenon occurs.
[0003]
Therefore, in order to prevent this, a so-called windshield device is provided in which a screen made of foamed resin, wire mesh, cloth, or the like is provided so as to cover the front surface of the microphone to prevent wind from hitting the microphone diaphragm and its surroundings. It is used (for a cloth covering a sound hole on the front face of a microphone, for example, see Patent Document 1).
[0004]
As described above, in the conventional windshield device for microphones, in order to maintain sound transmission characteristics, the windshield device is formed of a porous screen material such as urethane foam, a wire mesh, and a cloth. As a result, noise generated when the wind directly hits the microphone diaphragm is reduced.
[0005]
[Patent Document 1]
Japanese Utility Model Publication No. 64-52397 (page 3, FIG. 1)
[0006]
[Problems to be solved by the invention]
By the way, most of screen materials used for the windshield device for microphones are non-conductive materials such as plastics, cloths and non-woven fabrics, except for expensive and complicated materials such as metal mesh.
[0007]
However, since such a non-conductive material does not have an electrostatic shielding effect, for example, when it is installed in a housing of a mobile wireless communication device, a microphone is built in the mobile wireless communication device, such as a wireless transmission power amplifier. When installed in close proximity to a microphone, a problem arises in that a high-frequency signal reaches the microphone circuit and is mixed therein, thereby impairing a communication function such as intermodulation with a very low-power audio signal.
[0008]
In addition, as a windshield material used for a windshield device for a microphone, an expensive and cumbersome material such as a screen made of a metal screen or a screen configured to blend metal wires has been tried, but even in such a case, The adhesive used for mounting this is generally insulative, and requires a complicated construction method for connection with the conductive housing. Under such circumstances, those that satisfy both the windshield effect and the electrostatic shielding effect have hardly been realized.
[0009]
In view of the above circumstances, the present invention is easy to manufacture, has a large windshield characteristic and a large electrostatic shielding property, and can be installed particularly close to other electronic circuits, etc., and has a high degree of design freedom. An object of the present invention is to provide a microphone with a windshield and an electrostatic shielding function that can be widely applied to an apparatus, a measuring apparatus, a system, and the like, and an inexpensive windshield and an electrostatic shielding screen used for the microphone.
[0010]
[Means for Solving the Problems]
The microphone with a windshield and an electrostatic shielding function of the present invention is characterized in that a sheet-like screen formed of a sound-permeable material is attached to the front surface of the conductive housing so as to cover a sound hole provided in the front surface of the housing, and has a windshield function and A microphone having an electrostatic shielding function,
The screen has an outer diameter larger than the sound hole and smaller than a front surface of the housing,
The screen and the front surface of the housing are continuously coated with a conductive material.
[0011]
Thus, the screen is electrically connected to the housing to form a windshield and electrostatic shielding screen for the microphone, and the microphone can be provided with an electrostatic shielding effect due to conductivity without impairing the windshield characteristics. it can. Moreover, by making the size of the screen smaller than the surface of the housing, the screen and the housing can be easily electrically connected to each other by a simple post-processing of the continuous conductive coating.
[0012]
Further, the microphone with a windshield and electrostatic shielding function of the present invention is characterized in that the screen has a hole or a notch in a portion not covering the sound hole.
[0013]
Accordingly, the two members can be electrically connected by simultaneously and continuously coating the outer surface of the screen material provided with conductivity and the conductive housing to be mounted with the conductive material.
[0014]
Further, the windshield and electrostatic shielding screen of the present invention is formed in a sheet shape from a conductive sound-permeable material or an insulating sound-permeable material, and is mounted on the front surface of the conductive housing of the microphone provided with a sound hole, and the microphone is provided. A screen that imparts a windshield function and an electrostatic shielding function to the
The outer diameter is larger than the sound hole, and has a size smaller than the front surface of the conductive housing to be mounted,
The sound hole is fixed to the front surface of the housing so as to cover the sound hole, and is coated continuously with the front surface of the housing with a conductive material so as to be electrically connected to the front surface of the housing.
[0015]
Thereby, the windshield / electrostatic shielding screen forms a windshield / electrostatic shielding unit for a microphone by being electrically connected to the housing, and can provide a function as a windshield effect and an electrostatic shielding effect due to conductivity. it can. Also, by making the size of the screen smaller than the surface of the housing, the electrical connection with the housing can be easily made by a simple post-processing of the conductive coating.
[0016]
Further, the windshield and electrostatic shielding screen of the present invention is characterized in that a hole or a notch is provided in a part or a plurality of portions not covering the sound hole.
[0017]
Thereby, the screen material and the housing can be electrically connected at the same time.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a condenser microphone 1 having a windshield and an electrostatic shielding function according to an embodiment of the present invention. The condenser microphone 1 covers a sound hole 2 </ b> A on a front surface of a housing 2. And a sheet-shaped insulating screen (which constitutes a windshield and an electrostatic shielding screen) 3 made of a sound-transmissive material. It has a configuration that is coated.
[0019]
The housing 2 is formed of an appropriate conductive material such as a metal, and the above-described sound hole is formed in the center of the front surface for introducing an acoustic wave. Is fixedly provided.
Although the housing 2 of the present embodiment is formed of a conductive material such as metal, if formed of an insulating material, the entire housing 2 is provided with conductivity by an appropriate method such as metallization. There is a need to.
[0020]
An electrode 22 (hereinafter referred to as a microphone back electrode) is fixed to and supported by the support member 21 in a non-contact state with the housing 2. The microphone back electrode 22 is connected to an IC 25 for an impedance conversion electric circuit via a lead wire 22A, and an output terminal 22B is drawn out of the housing 2 from the IC 25 for the impedance conversion electric circuit. ing.
[0021]
A diaphragm ring 23 is attached to the inside of the housing 2 so as to be laminated on the support member 21, and the diaphragm ring 23 has a ground electrode (not shown) provided in contact with the housing 2. The vibration film 24 is fixed and supported.
[0022]
The screen 3 constitutes a windshield and electrostatic shielding screen, and is configured so as to enhance the function as a windshield effect and the electrostatic shielding effect due to conductivity for the condenser microphone 1. , Which can be installed in proximity to other electronic circuits (such as a wireless transmission power amplifier incorporated in a mobile wireless communication device) and covers the sound hole 2A provided on the front surface of the conductive housing 2 of the condenser microphone 1. It is installed in.
[0023]
The screen 3 is made of an insulating sound-transmitting plate having air permeability, that is, a non-conductive porous material such as cloth or non-woven fabric, and a conductive material such as carbon applied by a binder to make the sound conductive. In order to form a windshield and electrostatic shielding device for a microphone, after being fixed to the housing 2, the microphone 2 is coated with a conductive material 4, which will be described later, to collectively coat the housing 2 with the housing 2. To connect to. As described above, although the screen 3 of the present embodiment is a non-conductive material, the surface is made conductive by applying a conductive material, and is electrically connected to the conductive housing 2.
[0024]
As described above, the screen 3 used in the present invention is itself a conductive material such as a metal, or as in the present embodiment, imparts conductivity to an insulating base material. Either mixing carbon particles or the like into the base material, or applying a conductive coating mainly composed of a conductive substance such as carbon particles on the surface of the insulating material after formation, it is conductive and has sound transmission It has.
Therefore, in addition to the present embodiment, the screen 3 is made of a conductive sound-transmitting plate, that is, a conductive net made of a gas-permeable metal or the like, or a conductive porous material such as a punching metal or an ex-band metal. It may be formed.
[0025]
When a conductive sound-transmitting plate is used as the screen 3, the screen 3 itself has conductivity and can be electrically connected to the housing 2 in this state. Unlike the case where the screen 3 is formed of a non-conductive porous film such as cloth or nonwoven fabric, it is generally considered that it is not necessary to coat the screen 3 and the housing 2 with the conductive material 4 at a time.
However, since most of the adhesive used to fix the screen 3 to the housing 2 is insulative, as in the case of using an insulating sound-transmitting plate, unless the conductive adhesive is used, the conductive adhesive is used. Also in the case of the sound-transmitting plate, it is preferable that the screen 3 and the surface of the housing 2 are collectively coated with the conductive material 4 after the screen 3 is fixed to the surface of the housing 2 with an insulating adhesive. Thus, it is possible to avoid using an expensive conductive adhesive or the like to make sufficient electrical connection with the housing 2.
[0026]
The size of the screen 3 is naturally larger than the sound hole 2A. However, at the same time, in the present invention, the area of the screen 3 is formed smaller than (the surface area of) the front surface of the housing 2. .
That is, the screen 3 can be made of a conductive material or a non-conductive material, and after the screen 3 is mounted on a predetermined portion, a conductive coating is applied to the entire surface and the entire surface of the front surface of the housing 2 at a time. The surface is made conductive (even if formed of a non-conductive material) and is electrically connected to the conductive housing 2.
However, as described above, even if the screen 3 is conductive, most of the adhesive used for mounting is insulative. For this reason, conventionally, in order to make a sufficient electrical connection, an expensive and less flexible material such as a conductive adhesive had to be used. By making the surface smaller than the surface, the electrical connection can be easily performed by a simple post-treatment of the conductive coating without using an expensive conductive adhesive or the like.
[0027]
Furthermore, in the present embodiment, the screen 3 constituting the windshield and electrostatic shielding screen is formed of a material having air permeability, but in particular, a part of the screen 3 having or having conductivity. Alternatively, a plurality of portions may have a hole at a portion that does not cover the sound hole 2A. That is, the holes are larger than a large number of holes provided from the beginning on the whole of the screen 3 due to the air permeability of the screen 3. An operation and an effect that an electrical connection between the housing and the housing can be obtained.
[0028]
The conductive material 4 is used to electrically coat the screen 3 together with the front surface of the housing 2 to electrically connect the two, and is mainly made of a conductive substance such as carbon particles.
[0029]
As described above, according to the present embodiment, as shown in FIG. 1, a screen 3 made of an insulating nonwoven cloth is installed on the front surface of the housing 2 of the microphone 1 as a windshield of the microphone. In addition, the entire surface of the housing 2 is coated with a conductive coating over the front surface. Thus, by electrically connecting the screen 3 and the housing 2, the condenser microphone 1 is provided with a windshield and an electrostatic shielding function. In other words, the windshield effect and the electrostatic shielding effect are simultaneously performed. You can get it.
[0030]
Next, when the acoustic characteristics and the electrostatic shielding effect of the condenser microphone 1 configured as described above are examined, the acoustic characteristics conforming to IEC (International Electrotechnical Commission International Electrotechnical Commission) 651: 1979 TYPE1 are obtained. At the same time, even if the electrostatic shielding effect is close to 1 cm with respect to the transmitting section of the mobile phone (800 MHz band) during the transmitting operation, no inductive noise is detected in the microphone output signal, confirming the effectiveness of the present invention. .
[0031]
【The invention's effect】
As described above, according to the present invention, a breathable screen formed of a conductive sound-transmitting material or an insulating sound-transmitting material is attached to a front surface of a conductive housing provided with sound holes to provide a windshield function and static electricity. A microphone that has an electric shielding function and has a screen whose outside diameter is larger than the sound hole and has a size smaller than the front surface of the conductive housing to be mounted. The screen fixed to the front surface of the housing and the front surface of the housing are continuously coated with a conductive material.
[0032]
Therefore, according to the present invention, it is easy to manufacture, has a large windshield characteristic and a large electrostatic shielding effect, can be installed particularly close to other electronic circuits, etc., and has a high degree of design freedom. And a microphone that can be widely applied to systems and the like can be provided at low cost.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing a condenser microphone provided with a windshield and electrostatic shielding device according to an embodiment of the present invention.
[Explanation of symbols]
1 condenser microphone 2 housing 2A sound hole (acoustic wave introduction hole)
21 Support Member 22 Microphone Back Electrode 22A Leader Wire 22B Output Terminal 23 Diaphragm Ring 24 Microphone Vibration Film 25 IC for Electric Circuit for Impedance Conversion
3 (insulating) screen (windshield and electrostatic shielding screen)
4 Conductive materials

Claims (4)

A microphone provided with a windshield function and an electrostatic shielding function by attaching a sheet-like screen formed of a sound-transmitting material to the front surface of the conductive housing so as to cover a sound hole provided on the front surface of the conductive housing,
The screen has an outer diameter larger than the sound hole and smaller than a front surface of the housing,
A microphone having a windshield and an electrostatic shielding function, wherein a conductive material is continuously coated on the screen and the front surface of the housing. The microphone with a windshield and an electrostatic shielding function according to claim 1, wherein the screen has a hole or a notch in a portion not covering the sound hole. A screen formed of a conductive sound-transmitting material or an insulating sound-transmitting material in the form of a sheet, and attached to the front surface of the conductive housing of the microphone provided with sound holes to provide a windshield function and an electrostatic shielding function to the microphone. So,
The outer diameter is larger than the sound hole, and has a size smaller than the front surface of the conductive housing to be mounted,
The windshield and the static head are fixed to the front surface of the housing so as to cover the sound hole, and are continuously coated with a conductive material together with the front surface of the housing to be electrically connected to the front surface of the housing. Electric shielding screen. 4. The windshield and electrostatic shielding screen according to claim 3, wherein a hole or a notch is provided in a part or a plurality of parts not covering the sound hole.

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